1c-early

API cleanup

Changes:

• Added call_sync and field_or_call_sync helpers
• Turned most attribute-like methods into attributes
• Made all attributes synchronous
• Added create classmethods to most classes
• Added optional args to world.spawn_entity
• Allowed spawning of non-living entities
• Fixed player UUID lookups
• Chat event return value is now the chat message format for that event
• Bugfixes